Convenient methods of preparing complexes of the type (C,H,) Fe(dppe)X (dppe = Ph,PCH,CH,PPh,) are reported and some new complexes are described. The ,' Fe and (for X = SnCI,, SnBr,. and Snl,) the 119Sn Mossbauer spectra of these complexes have been recorded, and are discussed in relation to the spectra of analogous C,H,Fe(CO),X and C,H,Fe(CO) (L)X complexes (L = monodentate phosphine) which have been previously studied.THE substitution of carbonyl groups by tertiary phosphines in complexes of the type C,H,Fe(CO),X has been well studied, and many such substituted complexes have been ~haracterised.l-~ Disubstituted complexes are, however, more difficult to prepare by direct substitution than are monosubstituted complexes, and U.V. irradiation or extended periods of reflux in high boiling solvents are often r e q ~i r e d . ~, ~? ~In consequence, direct substitution can only be used as a method of preparing disubstituted
Cationic Low-spin Bis[l,2-bis(dial kylphosphino)ethane] iron(ir) Complexes tBy J o h n M.
The range of available ll9Sn Mossbauer data for the trichlorotin system has been extended. Variations of the Mossbauer parameters are rationalised by considering the effect of the donor ability of the ligand L in the complex LSnCI,. This approach is shown to be consistent with available i.r. and crystallographic data. The data strongly suggest that the Mossbauer centre shift does not provide a good distinction between formal SnII and SnIV species in many cases and that a valence-bond (hybridisation) approach is more meaningful. tin(1v) cornpound~.l-~ Their centre shifts are, in the main, less than 2.0 mm s-l and their quadrupole splittings a A
The original paper22 incorrectly reported 0.125 mol of Ag2O as being 15.5 g. The correct amount, used here, is required for the reaction to be completed in a reasonable length of time. CsChN2 is said to be very stable22 and we experienced no difficulty. However it is advisable to use care when subjecting the compound to extreme reaction conditions. (24) V. W. Day, K. J. Reirner. and A. Shaver, J . Chem. Soc., Chem. Commun., 403 (1975). (25) The first number in parentheses is the rms estimated standard deviation of an individual datum. The second and third numbers, when given, are the average and maximum deviations from the average value. respectively. (26) L. M. Haines and M. H. B. Stiddard, Adv. AIC50188P 57Fe Mossbauer spectra are reported for a number of six-coordinate iron(I1) isocyanide-carbene complexes of the type [Fe(CNMe)s(carbene)](PFs)z and [Fe(CNMe)4(carbene)2](PF6)2. The signs of the 57Fe QS for [Fe(CNMe)s[C-(VH2)NHMe]](PF6)2 and [Fe(CNMe)4[(CNHMe)2Y2HPh]] (PF6)2 are negative 2nd positive, respectively. The derived partial center shift (pcs) and partial quadrupole splittings (pqs) for carbenes indicate that they are very good 17 donors relative to all neutral ligands and poor 7r acceptors. In particular, our carbenes are better u donors and worse 7~ acceptors than M e N C . Using the point charge model including distortions, we attempt to explain the larger quadrupole splittings for the compounds containing chelating carbenes, and the unusual quadrupole splittings for "trans"and cis-Fe(o-phen)z(CN)z and Kz[Fe(o-phen)(CN)4]. A number of new adducts of ferrous phthalocyanine (FePc) have been isolated. These include mixed-ligand complexes LFePcL' [I-= a nitroso aromatic group, L' = n-butylamine or N-methylimidazole; L = cyclohexyl isocyanide, L' = N-methylimidazole; L = a phosphite, L' = n-butyiamine] and bis adducts LzFePc [where L is an isocyanide or a phosphite], The complexes have been characterized by elemental analysis, electronic spectra, infrared spectra, and proton magnetic resonance spectra. The ring-current-induced shifts found for coordinated nitrosobenzene have been analyzed and it is concluded that this ligand coordinates iron through the nitrogen lone pair. The rate of exchange between free and complexed nitrosotoluene in ( C H~C~H~N O ) F~P C (~-C~H~N H Z ) has been determined by observing the 'H NMR spectrum under intermediate exchange conditions. The exchange occurs via a dissociative path and the activation parameters for exchange are AH* = 20.1 f 0.2 kcal/mol and AS* = 14.2 * 0.2 eu.
84.6%) of crude crystalline substance was obtained, which was recrystallized from water to give 1.1 g (59.3%) of 6. This compound gave an identical ir spectrum and uv absorption pattern with those of 6 derived from 4-Ar-oxide 2, mp 167-170°, [<*]14d -65.4°( after 24 hr) (c 1.0, water).
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